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Design of semiactive seat suspension for agricultural machines
Zindulka, Martin ; Čížek, Petr (referee) ; Strecker, Zbyněk (advisor)
The thesis deals with design of a semiactive seat suspension system for an agriculture machines and design of dynamic model of the system, which includes real parameters of a magnetorheological (MR) damper. The dynamic model is a single degree of freedom model and it is made in program Matlab. In the model, response time of the MR damper and three control algorithms are implemented (two-state Skyhook, Skyhook linear approximation damper control and Acceleration Driven Damper control). Based on the results of the simulations, the damping characteristics are defined, and the MR damper is modified to achieve fast response time. A test seat is designed to test transmission of vibrations to the driver. The simulation results provide a comparison of efficiency of the seat suspension depending on the response time and control algorithm, as well as a comparison with a passive suspension system. On the designed test seat with MR damper with a fast response time, the vibration transmission is reduced up to 25 % compared with the best passive seat suspension setup.
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Dynamic properties of thermometers
Tomšej, Radek ; Závorka, Dalibor (referee) ; Himr, Daniel (advisor)
This bachelor thesis deals with temperature measurement. The introduction describes the individual methods including the principles on which the methods are based. Furthermore, it presents the suitability of these individual methods, including the properties of thermometers based on the given methods. The experimental part of the thesis evaluates the practical measurement of temperature and proposes the design methods of determining the temperature in a time much faster than the response time of the thermometer.
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Graphical Modifications of Response Options in online Questionnaire
Terchová, Petra ; Remr, Jiří (advisor) ; Hendl, Jan (referee)
This thesis deals with an issue of how can graphical modifications of response options in online questionnaire influence the respondents' answers. Online questionnaire as a data collection method offers a wide range of visual adjustments. Therefore, it is necessary for the graphical format to be treated with caution, because it can produce significant differences in respondents' answers. The goal of this thesis is to find out, with the help of two versions of online questionnaire that differ in the graphical format of response options, whether and what differences in answers these modifications produce. The attention is also payed to the response time differences. Together there are eleven modifications tested, each of them is represented twice. The analysis shows that the differences in graphical format of response options do influence the answers; there were 7 of 11 hypotheses confirmed. One of the surprising findings is that in the case of comparing the format of check boxes and the format of writing answers into text boxes, respondents answered with a maximum number of allowed answers in both version. This type of result was not expected in the case of the "writing into text boxes" format. Other findings show that some modifications influence more women than men, for example the use of a...
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Response time of thermometers
Novák, David ; Radil, Lukáš (referee) ; Foral, Štěpán (advisor)
The aim of the work is the analysis of the characteristics of resistive and termočlánkových sensors, the description of their principle, basic parameters, structural design and last but not least is probably the most important part of the work of the explanation, analysis and practical experiment to see the time constant of the sensor. In the first part of the thesis explains the basic concepts and principles of thermal quantities of phenomena. Then it is done the basic classification of methods of measuring temperature with the inclusion of the main points of the content of this work. The next section will deal with the main issues of the work. First comes an explanation of the nature of resistive sensors and is explained in the next chapter the principle of thermocouples. The following is the chapter on the construction of the sensors. Here is a design of the sensor for the dismantled the practical use in industry and in other applications.. In the next chapter is described in detail at the issue of the time constants of the sensor. This chapter contains not only an explanation of this concept, but also to derive equations for the description of sensor behavior important in changing the conditions of real traffic. The following is the part where they are dismembered influences affecting the time constant of the device. These effects can significantly affect the otherwise high accuracy thermometers mentioned above. The last chapter deals with practical measurement of time constants specified thermometers. The measurement was carried out in two different environments, in boiling water and warm air. The assessment of the results of the measurements showed that the time constant in an environment of boiling water is significantly smaller than in the case of hot air, and that for all of the measured objects.
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Server application to process data from a MySQL database and their interpretation
Gardian, Ján ; Zeman, Kryštof (referee) ; Červenák, Rastislav (advisor)
Diploma thesis is about creating server application that process and interprets data from the database. Main aim of such application is able to process a large number of database requests in real-time environment. Provided database contains records of measuring download speed and quality of mobile connection via different radio technology from various providers. Those measured data are sent from users all around the world and amount of data collected is still growing. Therefore created server application can adapt to increasing size of database thanks to aggregation. This method of aggregation and use of index in database tables are further discussed in the theoretical part. Mainly putting indexes in tables produce significant acceleration of processing database requests. Final product of this thesis is an application that consist of three components: a server application running aggregation, website that interprets measured data and back-end interface providing measured data as well. Data at the website are presented in form of graphs for different countries and used radio technologies. Web address and user manual for finished applications are provided in the fourth chapter of diploma thesis. In the last part of thesis are performed various speed tests of programmed application that confirm the effectiveness of selected and described methods to accelerate work with the database.
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Simulation of Traffic on Roads and Highways
Zajdák, Jiří ; Vícha, Karel (referee) ; Drahanský, Martin (advisor)
This thesis deals with a simulation of traffic on roads and highways. The thesis analyzes important concepts of road traffic law and their relation to simulation system. Further are here described problems of design and creation of traffic network which simulator uses. Work explains principles of models of behaviour of traffic participants which are extensible by force of plug-ins. The thesis also valorizes how many details is advisable to model the reality in particular parts of simulating system.
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Analysis of Real-Time Operating System Kernels Running on FITkit
Rajnoha, Peter ; Šimek, Václav (referee) ; Strnadel, Josef (advisor)
The project is dedicated to the identification of the problems found while building RT operating systems for use in embedded devices. The project's main topic is the possibility of using RT system in the FITkit platform and it also discusses individual problems and their possible solutions. One of the problems is the way of acquiring the timing information for tasks to ensure their RT properties. We have extended existing simulator for given microcontroller that is also part of the FITkit. The simulator can be used for detailed monitoring of the execution of individual tasks in the system based on dynamic analysis, collecting timing statistics for given blocks of the program or it can be extended by new modules. The RM scheduling mechanism has been integrated into the FreeRTOS system as an example by considering the knowledge of the concrete operating system and acquired timing information.
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Program for monitor testing
Matyáš, Pavel ; Prokeš, Aleš (referee) ; Michálek, Václav (advisor)
The goal of this term project are problems of LCD panels. The beginning of the term project is about theoretical description of particular types and features of actual LCD panels, origin of picture defects on computer monitors, measuring and picture quality testing methods of monitors. Practical part of project involves designing testing patterns and it's realisation in Borland Delphi development environment.
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